The timetabling problem consists in fixing a sequence of meetings between teachers and students in a given period of time, satisfying a set of different constraints. There are a number of different versions of the timetabling problem. These include school timetabling (where students are grouped in classes with similar degree plans), university timetabling (where students are considered individually) and examination timetabling (i.e. scheduling of university exams, avoiding student double booking). Several other problems are also associated with the more general timetabling problem, including room allocation, meeting scheduling, staff allocation and invigilator assignment. Many data formats have been developed for representing different timetabling problems. The variety of data formats currently in use, and the diversity of existing timetabling problems makes the comparison of research results and exchange of data concerning real problems extremely difficult. In this paper we identify e...